merge boost.heap
merge boost.heap from trunk
heap: merge from trunk
heap: merge from trunk
heap: merge fixes from trunk
Merge the heap redirects to release.

Not merging the addition to `libs/libraries.htm` just yet, as there are some
other changes to be merged first.
heap: merge fix from trunk
heap: merge documentation fix from trunk
heap: merge documentation fix from trunk
heap: merge fix from trunk
heap: merge fixes from trunk
heap: merge fix for #7233
heap: merge changes from trunk
heap: merge fixes from trunk
heap: merge changes from trunk
heap: merge changes from trunk
heap: merge changes from trunk
heap: merge fix from trunk
heap: merge changes from trunk